Millions of passengers on the West Coast mainline face a decade of ‘catastrophic’ disruption caused by work on the £50billion HS2 high-speed project, a damning dossier of official papers reveals today.

Train bosses also warn of delays and train shortages on the link between London, the North and Scotland and chronic passenger overcrowding on platforms at London Euston, one of Britain’s busiest stations.

Up to four out of 10 trains risk running late between 2016 and 2026 as preparation and construction work is carried out on the southern terminus of the proposed high-speed project.

Millions of passengers on the West Coast mainline face a decade of 'catastrophic' disruption caused by work on the £50bn HS2 high-speed project, a damning dossier of official papers reveals today

Campaigners say Euston will be turned into 'the Heathrow of rail' and that West Coast and commuter passengers will pay the price of the Government's high-speed 'folly'

Internal documents seen by the Mail reveal forecasts that show punctuality and performance will 'be likely to worsen by between 4 and 8 per cent’ though warns ‘bad days would be significantly worse'.

Until now, passengers have been unaware of the full extent to which their conventional long-distance and commuter lines face disruption while platforms at Euston are closed and services cut to make way for the new HS2 line.

Train companies including Virgin are understood to be furious at the prospect of disruption to one of the nation’s two main London to Scotland routes serving Birmingham, the North West of England and on to Glasgow.

Platform numbers at Euston reduced from 18 to 13, with the number of approach tracks reduced from six to four

Virgin train services will have to leave Euston just 25 minutes after arrival, leaving little time for servicing and cleaning

Passengers face a 22 per cent shortfall in capacity in suburban services to major commuter stations such as Harrow and Wealdstone, Watford, Hemel Hempstead and Berkhamsted.

Construction could result in a reduction in Birmingham and Manchester train from three to two an hour

The first phase of the high-speed line from London to Birmingham is due for completion in 2026, with a second phase, taking the line on a Y-shaped route to north west and north east England, due to be finished in 2032/33.

The Government also suffered a blow this week when Mr McLoughlin admitted for the first time that the HS2 Bill will now miss its target of being passed through Parliament before next year’s General Election.

Richard Houghton, of HS2 Action Alliance, who made the Freedom of Information request, said: ‘This is turning into a pantomime.

‘From the moment spades go in the ground, HS2 will needlessly create the very sort of chaos and capacity crisis it is proposed to avoid.’

A Department for Transport spokeswoman defended the Euston works noting: 'HS2 will deliver jobs, skills and regeneration, freeing up desperately-needed space on the railway, but we cannot continue to patch and mend.

'Londoners and commuters are calling for the regeneration of Euston, overcrowding on this line into London is one of the reasons why we're building HS2 – to create extra capacity, that will ‎benefit the millions that use the station every year.'

The spokeswoman added: ‘London Bridge, Blackfriars, Reading and Birmingham New Street have all seen major rebuilding work and the impact on rail users has been kept to a minimum. We will apply these lessons at Euston.’

A spokesman for HS2 said: ‘HS2 is vitally important to this country, it will deliver jobs, skills and regeneration. It will free up desperately-needed space on the existing rail network for intercity passengers, commuters and freight.

'We cannot continue to patch and mend our Victorian railway. We need to take the bold decisions now to secure our infrastructure into the next century. HS2 will be a vital artery benefitting communities right across the country.’

Details have emerged from documents obtained following a series of Freedom of Information requests by campaigners at the HS2 Action Alliance (HS2AA) and shown to the Mail. Pictured is a potential design for an HS2 train